1. Field of the Invention
This invention relates to apparatus for collecting hydraulic fluid that leaks past a seal member in a pressurized hydraulic fluid operated device, and more particularly to a vacuum operated leakage recovery arrangement that includes a leakage fluid collector adjacent to the seal and a vacuum pump connected with the collector through a conduit to draw the collected leakage hydraulic fluid to a suitable container to thereby avoid dripping of the leakage fluid onto the machine or onto other surfaces.
2. Description of the Related Art
In hydraulic devices having two relatively movable parts, such as an hydraulic cylinder adapted to slidably receive an inner member in the form of a solid rod or a hollow inner cylinder, flexible seals are typically carried by the interior surface of the cylinder and in surrounding and sealing relationship with the outer surface of the inner member to attempt to prevent the loss of hydraulic fluid between the relatively moving surfaces of the inner member and the cylinder. However, in actual practice, the inner member carries a thin film of hydraulic fluid on its outer surface as it moves outwardly from the cylinder, and when the inner member is once again moved into the cylinder, some of the thin film of hydraulic fluid that has accumulated on the outer surface of the inner member is wiped therefrom, and when sufficient hydraulic fluid has accumulated adjacent to the seal to overcome the surface tension of the fluid, some of the fluid falls by gravity to whatever machine parts might be thereunder, or, most commonly, onto the floor on which the machine is supported.
The leakage of hydraulic fluid is undesirable because it reduces the amount of fluid available for use and it ultimately requires that the reservoir of hydraulic fluid be replenished. Moreover, if the hydraulic device is located above another portion of the machine, the dripping of the hydraulic fluid takes place onto the underlying machine structure, where it could serve to accumulate dust and dirt, and ultimately find its way to the floor beneath the machine. In either case, the leakage of the hydraulic fluid is unsightly and undesirable, and although over the years many different types of seal configurations have been conceived and used in an effor to eliminate fluid leakage, as a practical matter all such seals permit some amount of fluid leakage, and the amount of leakage that occurs generally increases as the machine accumulates hours of use.
It is therefore desirable that some way be found to eliminate the undesirable accumulation of leakage hydraulic fluid, and it is a principal object of the present invention to provide an arrangement that accomplishes that result.
It is another object of the present invention to provide an hydraulic leakage fluid collection system in which fluid collectors are provided adjacent each seal, and conduits are provided to convey the collected hydraulic fluid away from the leakage site to a suitable container.
It is a still further object of the present invention to provide an hydraulic leakage fluid collection device in which an air operated vacuum pump is provided to suck the leakage fluid from adjacent the leakage point to a collection chamber.